Many theories about atomic structure have molded the current view of the
atom. the quantum model suggests that electrons

Orbit around the nucleus at specific energy levels

Explanation:

In the quantum model of the atom (Bohr's model), electrons orbit the nucleus at specific orbits corresponding to specific energy level - this means that an electron cannot be found in the space between two orbits.

Since each orbit correspond to a a precise energy level, this means that the spectrum of emission and absorption of an atom is discrete. In fact:

- When an electron jumps from a lower energy level to a higher energy level, it absorbs a photon whose energy is equal to the difference in energy between the two levels - so photons of only specific frequencies are absorbed

- When an electron jumps from a higher energy level to a lower energy level, it emits a photon whose energy is equal to the difference in energy between the two levels - so photons of only specific frequencies are emitted

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.